1. Field of the Invention
The present invention relates to a continuously variable speed ratio transmission wherein rotary motion is converted to oscillating motion, wherein one way roller clutches convert the oscillations back to unidirectional rotary motion.
2. Description of the Prior Art
Continuously variable transmissions (hereinafter referred to as CVT) have long been known. Some early examples, not of great relevance but illustrating basic planetary gear arrangements, include U.S. Pat. No. 954,453, issued to Arthur J. Morse on Apr. 12, 1910; U.S. Pat. No. 1,306,330, issued to William F. Drew on Jun. 10, 1919; U.S. Pat. No. 2,066,758, issued to Arthur B. Bassoff on Jan. 5, 1937; and U.S. Pat. No. 3,442,157, issued to Harry E. Novinger on May 6, 1969.
Of greater relevance are those CVT designs which convert oscillating motion of an eccentric member to unidirectional motion, and which provide separate means to vary eccentricity of this member. U.S. Pat. No. 3,087,355, issued to Roger J. J. Bassereau on Apr. 30, 1963, discloses a continuously variable transmission employing rectification of bidirectional rotation. Rectification is performed by a pawl and ratchet wheel assembly. Variation is accomplished by moving a plate to a condition of greater and lesser eccentricity with respect to an input shaft. However, the Bassereau invention is subject to surges in torque, or rippling. Rippling occurs as a result of the ratchet clutch driver being accelerated to a momentary peak value and then decelerated, torque being applied to the planetary gear through only a few degrees of rotation. The inventor's solution to this problem is to maximize the number of certain parts ("bearing ring 5", with reference to column 2, lines 6-8 of '355). While this solution mitigates the problem, it does not actually eliminate ripples.
U.S. Pat. No. 4,909,101, issued to Maurice C. Terry on Mar. 20, 1990, is a second example of rectified motion. Terry '101 employs overrunning clutches, as does the present invention, to accomplish rectification, in lieu of pawl and ratchet. The important function of addressing rippling is provided by neoprene members (see column 8, lines 50-63 of '101). This arrangement is seen to mitigate, by damping, such rippling, but, again, does not actually eliminate rippling.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.